<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div class="box">qqq
        <ul class="big">
            <li>1</li>
            <li>2</li>
            <li>3</li>
            <li>4</li>
            <input type="text" value="哈喽" id="but">
        </ul>
    </div>
</body><script>
          var box = document.querySelector('.box')
        //  var but = document.querySelector('#but')
        //  box.innerHTML='123'
        //  but.type='password'
        //  but.nodeValue='哈哈哈'

        //  console.log(but);
        
        box.setAttribute('tiechui','2211')
        console.log(box.getAttribute('tiechui'))
        box.removeAttribute('tiechui');
        

</script>
</html>